This would include representation and formulation of concepts, pedagogical techniques, knowledge of what makes concepts difficult or easy to learn, knowledge of students’ prior knowledge and theories of epistemology. Similarly, T and C taken together yield the construct Technological Content Knowledge, useful for describing teachers knowledge of how a subject matter is transformed by the application of technology (e.g., the use of simulations in physics). T and P together describe Technological Pedagogical Knowledge, or knowledge of how technology can support pedagogical goals (e.g., fostering collaboration).